<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<body>
    <script>
        class Person {
            constructor(name,age){
                this.name = name
                this.age = age
            }
            speak(){
                console.log(this)
            }
        }
        const p1 = new Person("a",4)
        p1.speak()
        const x = p1.speak
        x()
    </script>
</body>
</html>